100mg of a protein is dissolved in just enough water to make 10.0mL of solution.If this solution has an osmotic pressure of 13.3mm Hg at $25^{\large\circ}C$,what is the molar mass of the protein?(R=0.0821Latm $mol^{-1}K^{-1}$,760mm Hg =1atm)

Question

$\begin{array}{1 1}13980.4gmol^{-1}\\12980.4gmol^{-1}\\11980.4gmol^{-1}\\10980.4gmol^{-1}\end{array}$